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### Need to match number other than 1

by kprasanna_79 (Hermit)
 on Nov 29, 2007 at 10:11 UTC Need Help??

kprasanna_79 has asked for the wisdom of the Perl Monks concerning the following question:

Revered Monks,
Apologize for this silly question. I need to match a number other than 1. The input can be even four or five digit. But it should allow when it is not number 1
-Prasanna.K

Replies are listed 'Best First'.
Re: Need to match number other than 1
by tachyon-II (Chaplain) on Nov 29, 2007 at 10:22 UTC
```if ( \$number =~ m/^\d+\$/ and \$number != 1 ) {
# do stuff
}
else {
die "There can be only 1!"
}
Re: Need to match number other than 1
by moritz (Cardinal) on Nov 29, 2007 at 10:28 UTC
```m/\A
(?:
\d+  # if it starts with a 1,
# it has to be followed by other digits
|
\d* # otherwise one digit can be fine
)
\z
/x

Note that this matches only non-negative integers, and 01 is matched as well (no idea if that's OK or not, spec is unclear).

Note that you need some kind of anchoring (perhaps to a word boundary), but you don't necessarily need to anchor it to start and beginning of the string.

Re: Need to match number other than 1
by shmem (Chancellor) on Nov 29, 2007 at 10:19 UTC
I need to match a number other than 1.

So you started with matching 1 ? How did you do that?

Read perlre. While you're at it, read How (Not) To Ask A Question, then post the code you tried.

--shmem

```_(\$_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
/\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.(\$e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;\$e.e && print}```
Am I missing the point here or isnt it just
```if(\$number != 1) {

}

You miss the "match number" part.

```qwurx [shmem] ~ > perl -wle '\$foo = "bar"; print "not 1" if \$foo != 1'
Argument "bar" isn't numeric in numeric ne (!=) at -e line 1.
not 1

--shmem

```_(\$_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
/\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.(\$e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;\$e.e && print}```
Re: Need to match number other than 1
by grinder (Bishop) on Nov 29, 2007 at 10:35 UTC
```if (\$num =~ /^[^\D1]\d+\$/) {
print "does not begin with a 1\n";
}

The key to understanding this is that you are looking for anything that is not a non-digit or a 1. When you negate the negations in the above phrase, you'll see that it means you're matching 0, 2-9.

uh, update: that doesn't quite work, hang on a sec...

```if (\$num =~ /^(?:[^\D1]|1\d)\d*\$/) {
print "not a 1\n";
}

2nd update: now it works. It is instructive to see how the pattern had to be modified to exclude 1, but allow 10, 19, 1111, ...

• another intruder with the mooring in the heart of the Perl

That doesn't match any single digit number, nor will it match 10, which is not 1 either.
Re: Need to match number other than 1
by mwah (Hermit) on Nov 29, 2007 at 13:02 UTC
I need to match a number other than 1. The input can be even four or five digit. But it should allow when it is not number 1

After trying to interpret your question (what is meant by "number 1" anyway), I'll add another version of the "detection of 1 game":

``` ...
my \$num1 = qr{^ (?> ([\.\d]+) ) (??{\$1 == '1' ? '(?!)' : '' }) }x;
my \$txt1 = qr{^ (?> ([\.\d]+) ) (??{\$1 eq '1' ? '(?!)' : '' }) }x;

my @stuff = qw' 0101  1 123 1.1  01  222 21  1.000 ';

print
map \$_
. "\t as num: " . (/\$num1/ ? 'ok' : '--')
. "\t as txt: " . (/\$txt1/ ? 'ok' : '--')
. "\n",
@stuff;
...

Regards

mwa

You don't have to generate any code. The (?(COND)TRUE|FALSE) assertion fits the glove here. \$^N can be used instead of \$1 here, making it copy-paste safe.

I'd also like to draw some attention to Regexp::Common::number. These changes would make

```my \$num1 = qr{^ (?> ([\.\d]+) ) (??{\$1 == '1' ? '(?!)' : '' }) }x;
become
```use Regexp::Common qw/ number /;

my \$num1 = qr{^ (?> (\$RE{num}{dec}) ) (?(?{ \$^N != '1' })|(?!)) }x;
I reversed the logic in the COND block so that it reads better to me. "Match a number, the number isn't 1, done".

lodin

I tried that and got this warning:
```Argument "\x{d6d}\x{bef}" isn't numeric in numeric eq (==) at (re_eval
+ 2) line 1.
:)
Re: Need to match number other than 1
by GrandFather (Saint) on Nov 29, 2007 at 10:46 UTC
```if (\$theNumberUnderTest == 42) {
print "Matched a number other than 1\n";
}

Perl is environmentally friendly - it saves trees
Yeah, I'd have to say this answers the "question" by testing for the ultimate answer, to life, the universe, and everything; but what was the question?
Re: Need to match number other than 1
by tcf03 (Deacon) on Nov 29, 2007 at 12:58 UTC
```if ( \$number =~ /^\d*\$/ and \$number != 1 )
{
# not 1 stuff here
}
Ted
--
"That which we persist in doing becomes easier, not that the task itself has become easier, but that our ability to perform it has improved."
--Ralph Waldo Emerson
Re: Need to match number other than 1
by queldor (Acolyte) on Nov 29, 2007 at 13:46 UTC
reading it as 'Need to match number other than 1 digit'
```if( m{^\d{2,}\$} ) {
# do stufff
}
Re: Need to match number other than 1
by olus (Curate) on Nov 29, 2007 at 14:09 UTC
Reading it as having a sequence of 4 or 5 digits, as in '12345', and allowing sequences that do not have the '1', then simply:

```my \$sequence = '12345';
if( index(\$sequence, '1') >= 0 ) {
# found the 1 digit. Interrupt here.
}

--
olus
Re: Need to match number other than 1
by logan (Curate) on Nov 29, 2007 at 21:54 UTC
Re: Need to match number other than 1
by nimdokk (Vicar) on Nov 29, 2007 at 20:23 UTC
I don't know, this may be over-simplistic - but what about:
```if ( \$number > 1 ) {
print "\$number greater than 1.\n";
} elsif ( \$number < 1 ) {
print "\$number less than 1.\n";
} else {
print "\$number is 1.\n";
}
Re: Need to match number other than 1
by hangon (Deacon) on Nov 30, 2007 at 08:49 UTC

"Sometimes a cigar is just a cigar" Freud

```if (\$number - 1){
#do sometning
}
Re: Need to match number other than 1
by iomatrix (Initiate) on Nov 30, 2007 at 00:57 UTC
Easier to ask if it isn't 1 then if it is. if (not (\$var == 1)) { ...do whatever... } Chris (iomatrix)
Re: Need to match number other than 1
by xicheng (Sexton) on Dec 01, 2007 at 08:37 UTC
``` if (\$str =~ /^(?!1\$)\d+\$/) {
do_stuff(\$str);
}
Regards,
Xicheng

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